Wildflowers of Polokwane 2
Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"
As promised in my previous plant entry, here I will now tell you a bit more about four of Polokwane's special plant species. These four are endemic or near-endemic to the Polokwane Plateau, meaning they're found pretty much nowhere else. Some may turn out to actually be more widely distributed, seeing as how so much land around here is still unexplored, but for now, we know them only from this one small region. Now all these are indeed flowering plants; the euphorbias have much reduced flowers that are in structures called cyathia; the Ledebouria has small but typical five-petalled flowers arranged along a short flower stalk, and the Kleinia has a thistle-type flowerhead, with a mass of tubular flowers at the tip of a short inflorescence.
Let's begin with the Kleinia. Kleinia venteri was named a couple of decades ago by Ernst van Jaarsveld, who glimpsed these tiny plants here around Polokwane. I heard of them not long after that, from Pieter Winter, who showed me some pressed specimens in the herbarium of the University of Limpopo. They did not look like much and I sort of forgot about them … until the day, perhaps a year or two later, when I stumbled upon some of them in the veld. It was a small patch of land in the middle of my own suburb, surrounded by houses. The plants were tiny, but their flowerheads distinctive and I immediately realized I was looking at the same thing I'd seen in the herbarium, only alive. I was charmed! The species is very, very humble … the above-ground stems are rarely longer than 5 cm/2" and the small, succulent leaves are about 2.5 cm/1" in length. Below-ground they have a little tuber that survives the harsh, dry winter, sending up new leaves and stems the next spring. The flowers grow from the tip of the leafless stem at the end of winter. They are almost larger than the rest of the plant! They're creamy coloured, with the greenish stamens protruding from the tubular disk florets.
Kleinia is a small genus in the Daisy Family, the Compositae. Most of the South African species live here in the Limpopo Province. All of them are succulent. I've already written about the beautiful Coral Kleinia. The largest and most conspicuous species is the Sjambok Bush, Kleinia longiflora, which can grow to a big, succulent shrub a meter and a half in height and two metres in width. Its flowers are very similar to those of Kleinia venteri. The Kleinias are closely related to the genus Senecio, which is one of the largest plant genera in the world, numbering at present over 1 250 recognized species.
But how closely is our little plant actually related to longiflora and the others? Very little actual research has been done on venteri. This is why the good botanist folks at the University of Limpopo have decided to do a thorough study on this species. We will try and resolve its relationships and determine its conservation status. Classification-wise it is still a conundrum. Recently I've heard that it's been re-classified into a new genus, Curio, along with a few other Kleinias, but looking it up, online, I can't find it there, the Curios actually appearing to come from a different group that used to be included in Senecio. I hope we can sort that out. As for conservation, the main goal would be to determine how widespread it is and how many of them there are. I will hopefully be helping mainly with this, since I've already encountered a few different populations of them around town, and I hope to be able to explore the region intensively over the next few years. But for now, things are not looking good. The few patches where I've found it growing, have no protection: people are walking there, dumping rubbish, and in two places the municipality comes each year with big trucks to mow down the grass, often crushing the Kleinias under the wheels. The patches where they're less disturbed, are experiencing ecological alterations in the form of bush encroachment; the veld is not being burned regularly enough, and so more and more trees and shrubs are growing and shading out the little Kleinias. Without serious help, the species could soon disappear from the wild. We have at least a few plants in cultivation, and they are quite easy to propagate.
Our next species is Ledebouria crispa. Ledebouria is a genus of bulbs in the Hyacinth Family, including perhaps over 50 species, most of them found in north-eastern South Africa. My hometown of Polokwane features numerous species growing close to or along with each other. They're often found in grassland, and especially on rocky hills. They're small plants, some absolutely tiny. They're distinguished by their leaves which feature a wonderful variety of shapes and marking patterns. They have small flowers that can be greenish, cream or purplish. While the flowers are quite pretty, they're generally popular to grow for their beautiful leaves.
In this group, Ledebouria crispa is one of the smaller ones, in the veld rarely growing over 5 cm/2" tall. It can be recognized by the crinkly edges of its unmarked, narrow leaves. Its flowers and fresh fruit capsules are pinkish-purple. This species grows mainly in long crevices in rocks. The area where they grow has the rocks cropping out amidst grassland, the rock layers tilted so the exposed parts form long, parallel ridges. The ledebourias grow in the crevices dividing the tilted layers. There is often only a shallow layer of soil in these crevices, and sometimes the tops of the bulbs protrude from it. The species is social, each crevice hosting many individuals. They propagate themselves from seeds and also from adult plants budding into new bulbs at their bases.
While there are thousands of plants in the population that I know of, I only know them to grow in this one, small place. It is close to shopping centres, surrounded by roads and residential areas. There are plans for further developments which would destroy more of its habitat. I hope to be able to find some other populations of the species, but for now, it is critically dependent on this small patch to remain protected and undeveloped.
The very same patch of land also hosts Euphorbia groenewaldii. This spiny succulent also grows in crevices between rocks, but is somewhat more adaptable than the ledebouria, in often also growing in flat, open land. It is recognizable by its corkscrew-twisted stems. There is another species, Euphorbia tortirama, that is very similar, and part of the work we need to do over here is to resolve just how it is related and distinguished from that species. It may turn out to be the same species, which in a way would be good, since it would mean that it is more widespread and less rare than we think. I know of a few populations in our region, and they differ in certain respects. It would at any rate be a good idea to try to preserve all of the populations. The threat as everywhere is in their habitat getting developed, to be specific, turned into residential areas.
Our last special plant is Euphorbia clivicola. I've already written about it here so here I repeat only what's essential. Related to groenewaldii, it looks very different. Its stems are finger-like, not conspicuously angled or twisted, and not as thorny. The species can grow into large, cushion-like mounds measuring a meter in width, with hundreds of stems pressed tightly together. This species occurs just across a road from groenewaldii. It is amazing that on one side of that road you only get clivicola, on the other side of the road you get only groenewaldii. There are a couple of other populations of the species in our region but I've not yet seen them, a situation I hope to soon rectify.
In the eighties, there were more than three thousand individuals of this species in eastern Polokwane. The land where it occurs was then methodically turned into residential areas and shopping centres. Now, only a small piece of veld around some reservoirs remains, and even that is still shrinking as more people build their houses there. Many of them dump their rubbish in the veld, some even throwing it right on top of the clivicolas. The rubbish attracts rats, and the rats gnaw and damage the plants as well. We still recently managed to find over two hundred plants, but that's not a very robust population. Also, the veld is changing and becoming more crowded by trees and shrubs, the typical pattern of bush encroachment affecting much of northern South Africa. Euphorbia clivicola needs large, open grassland areas to grow in. Just protecting the land is not enough. There was a colony in a nature reserve not far from Polokwane. The reserve was proclaimed for the protection of large antelopes; the euphorbias were not a priority. In the end, the veld wasn't burnt frequently enough, the grass and bushes became too dense, the plants that survived the bush encroachment got trampled by the antelopes, and now the population is no more.
So these are our four special, endemic Polokwane plants. (There likely are more endemics waiting to be discovered.) We don't know much, scientifically speaking, about any of them. We still have to sort out their relationships, determine their distributions, ecological roles and growing/flourishing requirements. None of them get any official protection – none of them occur in the Polokwane Nature Reserve, the only substantial protected piece of land that we have. All of them are under pressure because of ever-expanding residential areas and other developments. Their situation is typical of that of many, many species of plants all over the world. It's a race against the clock to catalogue them, to try and save them before they're gone forever. We have lost and are losing so many species of plants. You may have heard of the 'extinction crisis' without having seen precisely what is at stake … well, plants like these are the 'face' of the problem. Humble as they are, these species are all quite unique, and irreplaceable should they disappear. And remember, plants are the foundations of ecosystems, on land and in the oceans. They are the ones who capture the sun's energy and makes the food on which everything else depends. Erode the diversity of the plants, and you also erode the diversity of the animals. Lastly, the natural vegetation of the world is the safeguard of its climate. All plants, from trees to herbs to algae, absorb carbon dioxide from the atmosphere and store it in their tissues. Destroying the vegetation releases carbon dioxide while also destroying the world's ability to re-absorb and store carbon dioxide. Wild countryside everywhere is getting destroyed, even as we release even more carbon dioxide into the atmosphere by burning fossil fuels. If we don't stop, we're set for climate chaos world-wide. Protecting the remaining wild land and its vegetation, and re-establishing natural vegetation wherever possible, is our best bet for avoiding this.